I create a new invoice, I choose a customer, i select a product, I click on save, I click on validate.

The invoice takes a sequence number, but the new buttons (send by email, register payment, etc) don't appears. Invoice form view stays in the same state... Grrrr! We have to refresh, click on other menuitems, sometimes, I have to restart the server...

I see that invoice lines disapear also.

All my custom modules are disabled.

SOmetimes, I can create 2 or 3 invoices without problem. I don't know why.

Thanks for your comment

UPDATE #1

I have disabled many modules and I have no problem now. When I will be sure of what is the guilty module, I will publish it here.